This invention relates to an image forming apparatus having a medium storing portion that stores a plurality of media (printing sheets or the like), and relates to a medium feeding mechanism.
There is an image forming apparatus having a sheet feeding tray called as, for example, a manual tray or a multi purpose tray (MPT). Such a sheet feeding tray is configured to support a plurality of media (printing sheets or the like) on a horizontal placing surface, when the sheet feeding tray is in use. The sheet feeding tray is housed in a main body of the image forming apparatus, when the sheet feeding tray is not in use. In order to guide both lateral ends of the medium, the sheet feeding tray has sheet guides raised substantially perpendicularly to the placing surface. Each sheet guide has a sufficient length in the feeding direction of the medium, and a sufficient height in the direction substantially perpendicular to the placing surface. Therefore, a sufficient recess space is provided in the main body of the image forming apparatus for preventing the interference with the sheet guides when the sheet feeding tray is housed in the main body of the image forming apparatus, as disclosed in, for example, Japanese Laid-Open Patent Publication No. 2004-123316 (see FIG. 2).
As the length of each sheet guide in the feeding direction increases, the effect of preventing the skew the medium is enhanced. As the height of each sheet guide increases, the amount of the media storable in the sheet feeding tray becomes large. However, if the size of each sheet guide increases, it is necessary to provide a large recess space in the main body of the image forming apparatus, and therefore the image forming apparatus becomes larger. Particularly, in recent years, the downsizing of the image forming apparatus is being developed, and components thereof become concentrated (as the image forming apparatus becomes highly functional), and therefore it becomes difficult to provide a large recess space in the main body of the image forming apparatus.